Results 171 to 180 of about 1,305 (202)

An analysis of multisource tropospheric hydrostatic delays and their implications for GPS/GLONASS PPP-based zenith tropospheric delay and height estimations

Journal of Geodesy, 2021
To obtain better zenith hydrostatic delay (ZHD) corrections for global navigation satellite system (GNSS) applications, seven types of Vienna mapping function 1 (VMF1) and VMF3-like ZHD models provided by the Vienna University of Technology (TU Wien, TUW), University of New Brunswick (UNB) and GeoForschungsZentrum Potsdam (GFZ) are evaluated.
Hongxing Zhang, Yunbin Yuan, Wei Li
openaire   +1 more source

Evaluation of zenith tropospheric delays estimated by different regression models

2022
Yapay zekâ ve makine öğrenimi alanındaki gelişmeler, GNSS uygulamalarındaki sorunlara alternatif çözümler sunmakta veya mevcut çözümlerin verimliliğini artırmaya imkân sağlamaktadır. GNSS’de karşılaşılan birçok hata vardır ve bu hatalar kullanıcılar için problem oluşturmaktadır. Troposferik gecikme bunlardan birisidir.
AKAR, Ali Utku, İNAL, Cevat
openaire   +2 more sources

Quantifying the impact of environmental loading on Zenith Tropospheric Delays in Europe

2022
<p>We assess the impact of the environmental loading on the Zenith Total Delay (ZTD) time series estimated within the second re-processing campaign of the EUREF Permanent GNSS Network (EPN). In particular, we used one solution provided by the ASI (Agenzia Spaziale Italiana Centro di Geodesia Spaziale, Italy), and two solutions provided by
Anna Klos, Janusz Bogusz, Rosa Pacione, Vincent Humphrey, Henryk Dobslaw   +4 more
openaire   +1 more source

Tropospheric zenith delay monitoring in GPS precise point positioning

SPIE Proceedings, 2009
Precise point positioning (PPP) has been demonstrated to be a powerful sensor to monitor tropospheric zenith delay (TZD). In the PPP, some unmodelled biases still remain in the GPS observables and will inevitably degrade the precision of tropospheric zenith delay estimation.
Qing-lin Zhu, Zhen-sen Wu, Zhen-wei Zhao
openaire   +1 more source

Prediction of Zenith Tropospheric Delay Based on BP Neural Network

2012
This paper used improved Levenberg-Marquart BP neural network technology to predict GPS tropospheric delay with the data of Beijing GPS data and meteorological data, which the input parameters are either space position (longitude, latitude, elevation) or space position, temperature, pressure.
Yong Wang, Lihui Zhang, Jing Yang
openaire   +1 more source

Comparison of Tropospheric Zenith Wet Delay from VLBI and GNSS Estimations

2021
<p>Tropospheric delay is one of the major error sources for space geodetic techniques such as Very Long Baseline Interferometry (VLBI) and Global Navigation Satellite System (GNSS). In this study, we compared the agreement of tropospheric zenith wet delay (ZWD) seasonal variations derived from VLBI and GNSS observations at 8 stations that
Vicky Jia Liu, Maaria Nordman, Nataliya Zubko   +2 more
openaire   +1 more source

New versions of the BDS/GNSS zenith tropospheric delay model IGGtrop

Journal of Geodesy, 2014
The initial IGGtrop model proposed for Chinese BDS (BeiDou System) is not very suitable for BDS/GNSS research and application due to its large data volume while it shows a global mean accuracy of 4 cm. New versions of the global zenith tropospheric delay (ZTD) model IGGtrop are developed through further investigation on the spatial and temporal ...
Wei Li, Yunbin Yuan, Jikun Ou, Yanju Chai, Zishen Li, Yuei-An Liou, Ningbo Wang   +6 more
openaire   +1 more source

Combination of long time-series of troposphere zenith delays observed by VLBI

Journal of Geodesy, 2007
Within the International Very Long Baseline Interferometry (VLBI) Service for Geodesy and Astrometry (IVS), long time-series of zenith wet and total troposphere delays have been combined at the level of parameter estimates. The data sets were submitted by eight IVS Analysis Centers (ACs) and cover January 1984 to December 2004.
Heinkelmann, R., Böhm, J., Schuh, H., Bolotin, S., Engelhardt, G., MacMillan, D., Negusini, M., Skurikhina, E., Tesmer, V., Titov, O.   +9 more
openaire   +4 more sources

A Zenith Tropospheric Delay Interpolation Method Considering Elevation

2023 3rd International Conference on Electrical Engineering and Control Science (IC2ECS), 2023
Zhuoya Liu, Shuzhou Xiao, Xin Luo, Kang Yan, Youzhuo Zheng   +4 more
openaire   +1 more source

Influence of tropospheric zenith delays obtained by GPS and VLBI on station heights

2002
The least-squares fit of VLBI data analysis reveals a high correlation between station height parameters and tropospheric zenith path delay parameters. Thus, the station heights estimated by a VLBI least-squares solution are severely affected if tropospheric refraction is modeled insufficiently or if there is a lack of observations at low elevations ...
J. Böhm, H. Schuh, R. Weber
openaire   +1 more source